9 research outputs found
Failure of Micaceous Waste Tailings Dam
The paper describes the failure and reconstruction of an 80 ft. high, 8 acre tailings impoundment in Western North Carolina. The darn was constructed using the upstream method of construction. The coarse fraction of the tailings was used as embankment construction materials; these consisted of coarse to fine sands. The fine fraction tailings consisted of low density, relatively low plasticity, layered fine sands and fine sandy silts with frequent inter bedding of micaceous silty clays. Although a 20.0 ft. section of the darn failed, the fine saturated tailings did not liquefy but rather slumped into the breach. Reconstruction was complicated because there was no convenient access to the toe of the darn. Since this darn had been previously studied and found to be marginally stable, the failure reinforces the need for the engineer to keep accurate records of telephone conversations and other correspondence to help protect himself from having any liability in the failure
International Consensus Statement on Rhinology and Allergy: Rhinosinusitis
Background: The 5 years since the publication of the first International Consensus Statement on Allergy and Rhinology: Rhinosinusitis (ICARâRS) has witnessed foundational progress in our understanding and treatment of rhinologic disease. These advances are reflected within the more than 40 new topics covered within the ICARâRSâ2021 as well as updates to the original 140 topics. This executive summary consolidates the evidenceâbased findings of the document. Methods: ICARâRS presents over 180 topics in the forms of evidenceâbased reviews with recommendations (EBRRs), evidenceâbased reviews, and literature reviews. The highest grade structured recommendations of the EBRR sections are summarized in this executive summary. Results: ICARâRSâ2021 covers 22 topics regarding the medical management of RS, which are grade A/B and are presented in the executive summary. Additionally, 4 topics regarding the surgical management of RS are grade A/B and are presented in the executive summary. Finally, a comprehensive evidenceâbased management algorithm is provided. Conclusion: This ICARâRSâ2021 executive summary provides a compilation of the evidenceâbased recommendations for medical and surgical treatment of the most common forms of RS
Functional evaluation of the various calculation methods for precompression stress
Precompression stress (sigma(p)) is commonly used as an indicator for the load carrying capacity of a soil and its stress history. Several calculation methods have been proposed to determine sigma(p), but they have proven to be not interchangeable. The aim of this study was to perform a functional evaluation of seven existing methods to test which method would be most recommended to assess soil strength in cultivated fields. This was achieved by investigating the relation of the obtained sigma(p) of undisturbed soil samples to other soil properties and stress history. Additionally, the robustness of the methods was evaluated by checking their sensitivity to perturbation of the measured strains. The two most commonly used methods, the Casagrande method and Gompertz model fit method, were found to be the least suitable to calculate sigma(p). These methods lack robustness and do not yield a significant relation with the relevant soil properties or stress history. Better results were obtained with Intersecting linear regressions or at the inflection point of a fourth-degree polynomial